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NVIDIA To Enhance Its X Render Support?

01-21-2010, 04:20 PM

Phoronix: NVIDIA To Enhance Its X Render Support?

While improved X Render support hasn't been specifically brought up by any users in our thread for What Do You Want From Linux GPU Drivers In 2010?, it looks like NVIDIA may be working on improving their X Render support in its binary graphics drivers. NVIDIA's X Render extension support is already quite good and fast after being revitalized in some driver updates last year, but recent work is signaling that they may be further polishing this support to help users with 2D acceleration. This afternoon two patches hit the xorg-devel list that were written by Robert Morell and reviewed by Aaron Plattner...

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Forcing vsync on both nvidia-settings and compiz settings (note, forcing not merely enabling) is known to cause such issues.

In any case, the 120Hz hack is evil and speaks more of a deficiency in compiz than anything else.

I am aware of what the 'hack' does to the compiz code. Compiz IMO is poorly written in regards to v-sync handling. The v-sync wait often jumps over an available Hz and went to wait for next. So enabling v-sync and allow it to auto detect refresh rate will often cap the screen update rate to half the actual refresh rate, say 30Hz, which is very jumpy. To workaround the v-sync wait deficiency, we try to let compiz pull v-sync signal twice as fast, this solves the under-syncing bug and gives you smooth update rate. There is nothing evil about it, compiz should in default pull twice as fast so we don't even need to manually specify the rate.

For portets43: Have you tried to disable v-sync in nvidia driver, enable v-sync in compiz, DISABLE screen refresh rate detection and manually set to 120Hz? This combination works for me for a variety of nvidia cards: 8800GTS, 8800GTX, 9800GT, GTX-260+, even 7600GT and FX5700 gives smooth compiz desktop

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For portets43: Have you tried to disable v-sync in nvidia driver, enable v-sync in compiz, DISABLE screen refresh rate detection and manually set to 120Hz? This combination works for me for a variety of nvidia cards: 8800GTS, 8800GTX, 9800GT, GTX-260+, even 7600GT and FX5700 gives smooth compiz desktop